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Internet of Things-Compliant Platforms for Inter-Networking Metamaterials
Published in Christos Liaskos, The Internet of Materials, 2020
In both topologies, the coordinating node is responsible for setting up the network and sending out beacons when operating in beacon-based mode (see next section). Extensions to the 802.15.4 standard (e.g., ZigBee) allow for more complex network topologies (e.g., clusters). Network topologies also dictate the device type of the participating nodes. The possible device types are Full Function Devices (FFD), which can act both as a network coordinator and a simple network participant, and Reduced Function Devices (RFD) which can only participate in a Star topology network, without being able to coordinate it. Within a project context, a Star topology can be used when covering geographically constrained areas with low-cost sensors, whereas if more reliability and larger area coverage is required, a peer-to-peer topology can be considered. However, peer-to-peer to networks are more complex to maintain and can introduce security vulnerabilities.
Distributed Data Structures (DDSs)
Published in Suman Saha, Shailendra Shukla, Advanced Data Structures, 2019
Distributed HashingA distributed hash table (DHT) is a class of a decentralized distributed system that provides a lookup service similar to a hash table: (key, value) pairs are stored in a DHT, and any participating node can efficiently retrieve the value associated with a given key. Responsibility for maintaining the mapping from keys to values is distributed among the nodes, in such a way that a change in the set of participants causes a minimal amount of disruption. This allows a DHT to scale to extremely large numbers of nodes and to handle continual node arrivals, departures, and failures. DHTs form an infrastructure that can be used to build more complex services, such as cooperative Web caching, distributed file systems, domain name services, instant messaging, multicast, and also peer-to-peer file sharing and content distribution systems. Notable distributed networks that use DHTs include BitTorrent’s distributed tracker, the Coral Content Distribution Network, the Kad network, the Storm botnet, the Tox instant messenger, Freenet and the YaCy search engine.
Blockchain Computing
Published in Vivek Kale, Digital Transformation of Enterprise Architecture, 2019
The blockchain is designed to run a peer-to-peer network on top of the Internet. A peer-to-peer network means that computers talk to each other directly without the need of a central server for information exchange. In this model there are no special nodes or hierarchy and each nodes requests information directly from respective nodes. Peer-to-peer networks are therefore decentralized and open. The blockchain network is therefore simply a collection of nodes running a block chain system protocol with decentralization of control as its core principle.
Blockchain-based ubiquitous manufacturing: a secure and reliable cyber-physical system
Published in International Journal of Production Research, 2020
Ali Vatankhah Barenji, Zhi Li, W. M. Wang, George Q. Huang, David A. Guerra-Zubiaga
This section illustrates the mechanism and key characteristics of the BCUM platform. We classify this mechanism into four main parts. namely workflow, mining process, CYPs communication protocol (autonomous agent) and service connection. Figure 5 illustrates the BCUM mechanism in detail. The key characteristics of the proposed BCUM are defined as follows. Cryptography: transactions on the BCUM achieve authenticity, trust and irrevocability via mathematical computations.Immutability: on the BCUM, transactions cannot be deleted or altered.Decentralised computing infrastructure: computing infrastructure on the BCUM is decentralised; mining nodes and edge nodes are geographically distributed. This computing infrastructure can create independent processes and make computational decisions irrespective of what other peer computing nodes may decide.Peer-to-peer network: in these networks, participating nodes communicate with each otherdirectly, without a central or intermediate node or entity.Decentralised database: each participating partner always has access to the distributed database in its entirety. No single party controls the database, and every party can verify or regenerate it if required, without a central intermediary.